The invention pertains to a reflector used with a light source in a light fixture. More particularly, the invention pertains to a concave light reflecting device.
Uniform illumination along a defined horizontal or vertical plane has been the focus of several different configurations for luminaires. It is well known that light rays disperse as they travel away from a luminaire. This requires greater intensity or candle power directed at points in the plane that are further away in distance from the luminaire to maintain uniform illumination across the plane. The inverse square law, with cosign correction, defines the magnitude of illumination along the plane, E=(I/d.sup.2) cos .theta.. Satisfying the inverse square law for uniform illumination along the plane requires that the luminaire provide 13.245 times the intensity or candle power at angle .theta. of 65.degree. than is provided at nadir.
Various designs and geometric shapes for reflectors have been used to attempt to achieve uniform illumination across a plane. These designs include combining parabolic, elliptic, circular and cylindrical sections as in U.S. Pat. Nos. 3,679,893; 4,027,151; and 4,229,779.
The aim in designing a reflector device is maximizing the amount of light out of the device with minimum glare while maintaining maximum efficiency to avoid decreasing lamp life.